Complexes of

ABSTRACT

COMPLEXES OF SELECTED METALS, PHOSPHINES, AND ONE OF THE ANIONS B9H14-OR B9H12S-WHEREIN THE METAL IS COPPER, SILVER OR GOLD AND THE ORGANIC GROUP OF THE PHOSPHINE IS (ARYL) OR ALKARYL.) PHENY. THESE COMPLEXES ARE PREPARED BY REACTING A SALT OF THE POLYBORON ANION WITH A SALT OF THE METAL IN THE PRESENCE OF THE PHOSPHINE AND AN INERT SOLVENT. THE COMPOUNDS ARE USEFUL AS METAL FILM-PLATING AGENTS.

United States Patent 015cc Re. 27,465 Reissuecl Aug. 22, 1972 27,465 COMPLEXES OF B H OR B H S- WITH SELECTED METALS AND PHOSPHINES Frank K. Klanberg, Wilmington, DeL, assignor to E. I. du Pont de Nemours and Company, Wilmington, Del. No Drawing. Original No. 3,450,733, dated June 17, 1969, Ser. No. 601,326, Dec. 13, 1966. Application for reissue Feb. 26, 1971, Ser. No. 119,424

Int. Cl. C07f 1/08, 1/10, 1/12 U.S. Cl. 260-430 7 Claims Matter enclosed in heavy brackets II] appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE Complexes of selected metals, phosphines, and one of the anions B H or B H S wherein the metal is copper, silver or gold and the organic group of the phosphine is [aryl or alkaryL] phenyl. These complexes are prepared by reacting a salt of the polyboron anion with a salt of the metal in the presence of the phosphine and an inert solvent. The compounds are useful as metal film-plating agents.

This invention relates to novel metal-organic compounds. More specifically, the invention concerns complexes of B H or B H S with certain metals and phosphines, and to a method for their preparation.

The novel complexes of this invention are compounds represented by the formula wherein Z represents a polyboron anion selected from the class consisting of B H and B H S-; M represents a metal selected from the class consisting of copper, silver and gold; P represents phosphorus; and each R represents [a group of 6-12 carbon atoms selected from the class consisting of aryl and alkaryl. The R groups can be the same or different] phenyl.

The novel compounds of the invention are prepared by reacting a salt of the polyboron anion (Z) with a salt of the metal (M) in the presence of the phosphine (R P) and [in] an inert solvent.

More specifically, the polyboron reactant can be represented by the formula MZ, i.e., MB H or MB H S wherein M is a cation selected from the class consisting of alkali metal and R,,'NH,, wherein n is a cardinal number of -4, inclusive, and [the cations] R is lower alkyl. The R groups in the cation R,,NH., can be the same or different and the cations are represented by tert-butylammonium, diisopropylarnmonium, triethylammonium tetramethylammonium, and the like.

The anionic portion of the metal salt of M depends upon which metal M represents. 'For example, when M is copper (II), the metal salt reactant can be represented by the formula CuX wherein X is one equivalent of an anion selected from the class consisting of chloride, bromide, nitrate, sulfate, formate, acetate, lactate and tartrate. When M is silver, the metal salt reactant can be represented by the formula AgX wherein X is one equivalent of an anion selected from the class consisting of nitrate, acetate, sulfate and fluoride. Lastly, when -M is gold, the soluble metal salt reactant can be represented by the formula AuX wherein X represents an anion such as chloride or bromide; or by the formula MAuX wherein M" is alkali metal and X is defined as above. Because of their greater solubility, nitrate and fluoride are preferred X values.

For convenience, the process is usually carried out at room temperatures, e.g., 20-30 C., or slightly higher temperatures, e.g., up to 50 C. The latter range is sometimes useful for effecting increased dissolution of some of the reactants. The temperature range, however, is not critical and higher or lower temperatures may be used, but present no advantage.

Pressure is not critical and solely for convenience, atmospheric pressure is ordinarily employed.

[Nor is the ratio of reactantscriticaL] Usually, for optimum results, approximately stoichiometric ratios are used. As seen in the examples, the order of addition of the reactants is not critical and they can be combined in any sequence or all mixed together simultaneously.

Operable solvents include water, polar organic solvents that are at least partially miscible with water, and mixtures of the two. Examples of such polar solvents include lower alkanols such as methanol, ethanol and isopropyl alcohol; cyclic ethers such as dioxane and tetrahydrofuran; open chain polyethers such as [1,2-dimethoxymethane] 1,2-dimeth0xyethane and di(2-ethoxyethyl)ether; and lower alkanenitriles such as acetonitrile and propionitrile.

All products of the invention are relatively insoluble in the reaction medium and usually precipitate immediately when all the reactants are in mutual contact. The product can then be isolated by filtration and purified by recrystallization as shown in the examples.

Representative [polybaron] polyboron reactants in clude NH4B9H12S, NH4BQH14, NaB H S, NaB9H14, KBQHIZS, KBgHm, LiBgH Li BgHmS, and the like. Preferably, the cation M is cesium. The reactant CsB H S can be prepared by dissolving sulfur (6 g.) in warm aqueous ammonium sulfide (500 ml., 20% and cooling, filtering and treating the resulting solution with decaborane(14) (24 g.) while stirring and cooling in an ice bath. The decaborane is added slowly and when addition is complete, excess 50% aqueous cesium fluoride is added and the resulting precipitate is collected by filtration and recrystallized from water to give CsB H S. RbB H S can be prepared by replacing the cesium fluoride with rubidium fluoride. The ammonium and the other alkali metal salts of B9H12S can be prepared from the cesium salt by conventional cation exchange techniques.

The same cations as listed in the foregoing paragraph are also representative of the cations of the B9H14 salts used in the process of this invention. The M'B -H salts can be prepared generally as described in Benjamin et al., J. Amer. Chem. Soc. 85, 2674 (1963). The salts described therein can be subjected to cation exchange to obtain all the M cation salts.

[Representative phosphines (R 1 both as reactants and complexed ligand groups in the compounds of the invention, include triphenylphosphine, tritolylphosphine (o, mand p), tris(2,5 xylyl)phosphine, tris(2,4, 6-trimethylphenyDphosphine, phenyldi-p-tolylphosphine, diphenyl-p-tolylphosphine, tris(1 naphthyl)phosphine, tris(biphenylyl)phosphine, and the like] The novel compounds of this invention are colorless crystalline solids with definite melting points.

The products and process of this invention are illustrated in further detail in the following examples:

EXAMPLE 1 s s)s ]3 9 12 A solution of CsB H S (3 g.) in 30 ml. of ethanol was added to a mixture of triphenylphosphine (8 g.) and CuSO, (1.6 g.) in 150 ml. of ethanol and 50 ml. of Water. A white precipitate formed, which was separated and recrystallized first from 100- ml. of tetrahydrofuran and then from ml. of 1,2-dimethoxyethane. The yield was alculated diamagnetic susceptibility obtained by a sumiation of the atomic increments expressed as Pascal onstants was 10 0.61:0.02.

A sample of [(C H P] Cub H S prepared in the tanner described above was found to have an ultraviolet bsorption spectrum of xg F =275 A. (c, 19230 2620 A. (6, 21950 tagnetic susceptibility of 10 he B nuclear magnetic resonance spectrum showed a :road plateau with a maximum at 54 ppm. The inrared absorption spectrum (KBr wafer) showed B-H vbsorption at 2555 cm.- (terminal hydrogen) and 2200 :m. (bridging hydrogen).

A solution of [CaB H S] CSBQH .5 (2.7 g.) in 40 ml. f a 1:1 by volume mixture of ethanol and water was dded to a solution containing 15 g. of triphenylphosphine nd 1.7 g. of silver nitrate. The solid that precipitated was xtracted with 300 ml. of warm tetrahydrofuran. The aixture was filtered and the filtrate was concentrated ntil crystals precipitated. This crystalline solid was eparated and dissolved in 300 ml. of warm chloroform. Leduction of the volume to 50 ml. with chilling caused solid to precipitate. The solid was separated by filtration nd dried to give 5.6 g. of small [while] white crystals of (C H P AgB H S, darkened above 180 C. nd melted with decomposition at 190192 C.

Analysis.Calcd. for C H AgB P S: C, 62.2; H, 5.5; 9.0; B, 9.4; Ag, 10.4; S, 3.1. Found: C, 62.5; H, 5.8; 8.7; B, 9.5; Ag, 10.6; S, 3.2.

The infrared absorption spectrum (KBr wafer) showed l-H absorption at 2555 and 2425 cm." (terminal hyrogen) and at 2275 cm. (bridging hydrogen).

EXAMPLE 3 Triphenylphosphine (6 g.) in 100 ml. of ethanol was dded to a solution of NaAuCh-ZH O (3 g.) in 40 ml. f a 3 :1 by volume mixture of ethanol and water. A small mount of solid precipitated. The mixture was filtered, nd to the filtrate was added 2 g. of CSB H S, dissolved n a mixture of ml. of ethanol and 10 ml. of water. A thite precipitate was obtained which was collected and ecrystallized from 40 ml. of 1,2-dimethoxyethane to ive 2.7 g. of [(C H P] AuB H S as colorless crystals lhiCh melted at 181-183 C. with decomposition.

Analysis.Cald. for C H AuB P S: C, 57.6; H, 5.1; 8.3; B, 8.7; S, 2.9; Au, 17.5. Found: C, 57.9; H, 5.1; 7.9; B, 8.6; S, 2.9; Au, 17.5.

The infrared absorption spectrum (KBr wafer) showed i-H absorption at 2555 and 2425 cm. (terminal hyrogen) and absorption at 2315 cmf The observed diamagnetic susceptibility was ompared to a value calculated from Pascals constants of 0.61:0.22. Crystals of product were triclinic, with the arameters: a=13.43 A.; b=19.863 A.; c=11.180 A.; =l03.75; B=107.68;'y=86.63; Z=2. The calculated ensity was =1.384; while the experimental density was etermined to be =1.420.

Copper sulfate (1.6 g.) in 50 ml. of water was mixed with triphenylphosphine (5.2 g.) in ml. of ethanol, and CSB H (2.4 g.) was added to the mixture. The resulting White precipitate was separated and dissolved in 75 ml. of warm tetrahydrofuran. The solution was con centrated until a solid precipitated. The solid was separated by filtration and purified by recrystallization from an acetonezcyclohexane (2:1) mixture. The recovered material (2 g.) was recrystallized from 1,2-dimethoxyethane to give 0.7 g. of colorless crystals of Another less pure crop of 0.6 g. was obtained from the mother liquor. The pure solid melted with decomposition at 154-156 C.

Analysis.Calcd. for C H B CuP C, 67.4; H, 6.2; P, 9.7; B, 10.1; Cu, 6.6. Found: C, 67.7; H, 6.2; P, 9.3; B, 10.2; Cu, 6.7.

The UV absorption spectrum in CH CN showed only one peak, at 2670 A. (e, 24500). The B N.M.R. spectrum displayed a broad peak at 41.4 ppm. The infrared absorption spectrum showed B-H absorptions at 2555 cm. (terminal hydrogen) and 2200cmr (bridging hydrogen).

EXAMPLE 5 A solution of CSB H (2.7 g.) in 50 ml. of ethanol and 10 ml. water was rapidly added to a mixture of 15 g. triphenylphosphine and 1.7 g. of silver nitrate in ml. of ethanol and 10 ml. of water. The resulting white solid precipitate was separated by filtration and taken up in 220 ml. of warm tetrahydrofuran, insolubles being removed by filtration. The tetrahydrofuran filtrate was concentrated toabout one-third of its original volume. At this point, small crystals started to precipitate. They were separated by "filtration and recrystallized from ml. chloroform, and subsequently from 100 ml. tetrahydrofuran. Yield: 7.0 g. of colorless crystals of (in two crops), M.P. 187189 C. with decomposition.

Analysis.-Calcd. for C H AgB P C, 64.5; H, 5.9; P, 9.2; B, 97; Ag, 10.7. Found: C, 64.9; H, 6.4; P, 8.4; B, 9.1; Ag, 10.2.

The B N.M.R. spectrum showed a broad peak centered at 5:40 ppm. The infrared absorption spectrum showed B-H absorption at 25 55 cm. with a shoulder at 2440 cm.- (terminal hydrogen) and at 2275 cm. (bridging hydrogen).

EXAMPLE 6 s 5)s ]3 s 14 A solution of NaAuCl '2H O (3.0 g.) in 40 ml. of ethanol was slowly added to a solution of triphenylphosphine (12 g.) and CsB l-l (2 g.) in 220 ml. of a 10:1 by volume mixture of ethanol and water. The resulting crude brownish solid precipitate was separated and recrystallized four times from 1,2-dimethoxyethane to give 2.0 g. of colorless crystals of [(C H P] 3AuBgH14 which melted at 173175 C. with decomposition.

Analysis.Calcd. for C H AuB P C, 59.2; H, 5.4; B, 8.9; P, 8.5; An, 18.0. Found: C, 59.3; H, 5.7; B, 8.8; P, 8.0; Au, 18.0.

The infrared absorption spectrum showed B-H absorption at 2555 and 2440 cm.- (terminal hydrogen) and absorptions at [absorption] 2315 and 2250 cm.-

By employing the procedure set forth in the foregoing examples, all the compounds of this invention can be prepared.

The compounds of this invention are useful as metal film plating agents. For example, a solution of in dimethyl sulfoxide on exposure to air for about a day deposited a thin film of gold upon a cleaned glass and metal surface. Under similar conditions, a solution of wherein Z represents a polyboron anion selected from the class consisting of B H and BgH12S M represents a metal selected from the class consisting of copper, silver and gold; P represents phosphorus; and each R represents [a group of 6-12 carbon atoms selected from the class consisting of aryl and alkaryL] phenyl.

[2. Compounds of claim 1 wherein R is aryL] [3. Compounds of claim 1 wherein R is phenyL] 4. The compound of claim 1 having the formula s s s ]3 9 14 5. The compound of claim 1 having the formula a )s ]s a 12 6. The compound of claim 1 having the formula e 5)3 1a 9Hn 7. The compound of claim 1 having the formula 6 5 s l'a s m 8. The compound of claim 1 having the formula e 5)s ]a a 14 9. The compound of claim 1 having the formula e s )3 a 9 12 References Cited The following references, cited by the Examiner, are of record in the patented file of this patent or the original patent.

UNITED STATES PATENTS 3,217,023 11/1965 Miller 260430 X 3,296,260 3/1967 Knoth 260-430 X 3,328,422 6/1967 Knuth 260-430 X 3,418,346 12/ 1968 Parshall 260-429 OTHER REFERENCES Cariati et al.: Gazz. Chim. et al., vol. 95, pp. 3-15 (196-5).

Davidson: Chem & Ind., pp. 2021-22 (1964).

Cariati et al.: Gazz. Chim. Ital., vol. 95, pp. 201-205 (1965).

TO BIAS E. LEVOW, Primary Examiner H. M. S. SNE-ED, Assistant Examiner US. Cl. X.R. 

